The present invention relates to a polarizing filter control mechanism. More particularly, the present invention relates to a polarizing filter control mechanism to automatically reduce reflected light during operation of a photographic apparatus.
The effects of reflected light have long been a common problem for both professional and novice photographers and videographers alike. When a subject to be photographed is surrounded by a reflective background, such as glass windows, light is reflected back towards the photographer. This reflected light corrupts the resulting photographed image and makes it difficult to identify the subject.
Light shining from a reflective surface corrupts a photographic image because such light is reflected at angles perpendicular to the surface of incidence of light. One way to eliminate reflected light is to place a polarizing filter between the photographer and the subject to be photographed. The polarizing filter eliminates reflected light by allowing only unilateral, linear polarization light to penetrate the camera. Use of a polarizing filter is therefore widely known as a method to eliminate the effects of reflected light. For example, in conventional photographic and video cameras, a polarizing filter is placed in front of a lens. The polarizing filter is then manually rotated by the user to a rotational angle that minimizes the intensity of the reflected light.
Use of such a manual polarizing filter can be tedious and awkward. First, a user must manually rotate the polarizing filter to an angle that minimizes the reflected light. At the same time, the user must also visually verify that the intensity level of reflected light is at a minimum. Having to visually inspect the intensity of reflected light distracts the user's attention from the rotation position of the polarizing filter. As a result, the minimizing rotation angle setting is impaired. Likewise, having to verify the polarizing filter rotation position distracts the user's attention from verifying the intensity of reflected light. As a result, the minimizing intensity level is impaired.
In addition, photographic opportunities are often missed during manual operation of the polarizing filter. For example, when using a front element focusing lens, the polarizing filter sometimes rotates with each focusing operation. Therefore, the polarizing filter must be manipulated again after the focusing operation.
In some instances, the photographic subject may be moving. For example, an occupant of a car may be taking photographs of the outdoors while looking through a window of the car. The intensity of the reflected light periodically changes as the subject moves. The user must therefore operate the polarizing filter while following the subject. Since the subject is moving, the user must manually operate the polarizing filter in addition to the focusing and zooming operations. Having to focus one's attention simultaneously to all these operating factors can be overwhelming. Many different types of element focusing lens and front element zooming lens can be used. But none help to alleviate this overwhelming effect. Moreover, during video photography, in particular, it is difficult for a photographer to operate the polarizing filter and to follow the subject.